The TGF-beta superfamily regulates a variety of cellular functions that underlie embryonic development and tissue homeostasis. It is well known from knock out animal studies that TGF-beta 2 is important for kidney development, especially tubulogenesis. The type III TGF beta receptor is a critical co-receptor of TGF-beta 2, and has the ability to regulate other TGF-beta superfamily signaling. Through immunohistological staining, we show the type III receptor is also expressed extensively in the kidney tubular epithelial cells, implying an important role in adult kidney. Unfortunately, there is no data so far directly addressing the role of the type III receptor in kidney. This proposal will 1) investigate the biochemical characteristics of type III TGF-beta receptor, its interaction with different TGF-beta ligands and other receptors, 2) examine the expression and function of the type III TGF-beta receptor in normal as well as diseased kidneys, using a unique conditional knock out mouse model we have generated. Information we gained from these experiments will be important in our in-depth understanding of TGF-beta and kidney biology. [unreadable] [unreadable]